Hostname: page-component-8448b6f56d-mp689 Total loading time: 0 Render date: 2024-04-23T08:22:53.191Z Has data issue: false hasContentIssue false
  • English
  • Français

Middlebackite, a new Cu oxalate mineral from Iron Monarch, South Australia: Description and crystal structure

Published online by Cambridge University Press:  02 July 2018

Peter Elliott
Peter Elliott*
Affiliation:
Department of Earth Sciences, School of Physical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
*
*Author for correspondence: Peter Elliott, Email: peter.elliott@adelaide.edu.au
Get access Rights & Permissions [Opens in a new window]

Abstract

Middlebackite is a new supergene mineral formed in the upper levels of the Iron Monarch quarry, South Australia. It occurs as aggregates of blue, prismatic crystals up to 0.3 mm across comprising individual crystals up to 0.05 mm in length associated with atacamite and mottramite. Crystals are translucent with a vitreous lustre and have a pale blue streak. Middlebackite is brittle with one perfect cleavage and uneven fracture. Mohs hardness is ~2. The calculated density is 3.64 g cm–3. Crystals are biaxial (+) with α = 1.663(4), β = 1.748(4) and γ = 1.861(4) (measured in white light). The calculated 2V is 86.7°. Pleochroism is X = colourless, Y = very pale blue and Z = dark sky blue; Z > Y > X. The empirical formula unit, based on six oxygen atoms per formula unit is Cu2.00(C2O4)Cl0.02(OH)1.98. Middlebackite is monoclinic, space group P21/c with a = 7.2597(15), b = 5.7145(11), c = 5.6624(11) Å, β = 104.20(3)°, V = 227.73(8) Å3 and Z = 2. The five strongest lines in the powder X-ray diffraction pattern are [d(Å), (I), (hkl)]: 7.070 (16) (100), 3.739 (100) (11$\bar{1}$), 2.860 (18) (020), 2.481 (12) (12$\bar{1}$) and 2.350 (9) (300). The crystal structure was refined from synchrotron single-crystal X-ray diffraction data to R1 = 0.0341 for 596 observed reflections with F0 > 4σ(F0). The structure is based on sheets of edge- and corner-sharing octahedra parallel to the bc plane. Sheets link in the a direction via oxalate anions.

Keywords

middlebackitenew mineral speciescopper oxalatecrystal structureIron MonarchSouth AustraliaAustralia
Type
Article
Information
Mineralogical Magazine , Volume 83 , Issue 3 , June 2019 , pp. 427 - 433
Copyright
Copyright © Mineralogical Society of Great Britain and Ireland 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Associate Editor: František Laufek

References

Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters obtained from a systematic analysis of the Inorganic Crystal Structure Database Acta Crystallographica, B41, 244–247.Google Scholar
Bruker, (2001) SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.Google Scholar
Burns, P.C. and Hawthorne, F.C. (1996) Static and dynamic Jahn-Teller effects in Cu2+ oxysalts. The Canadian Mineralogist, 34, 1089–1105.Google Scholar
Chisholm, J.E., Jones, G.C. and Purvis, O.W. (1987) Hydrated copper oxalate, moolooite, in lichens. Mineralogical Magazine, 51, 715–718.Google Scholar
Christensen, A.N., Lebech, B., Andersen, N.H. and Grivel, J-C. (2014) The crystal structure of paramagnetic copper (II) oxalate (CuC2O4) formation and thermal decomposition of randomly-stacked anisotropic nano-sized crystallites. Dalton Transactions, 43, 16754–16768.Google Scholar
Chukanov, N.V., Aksenov, S.M., Rastsvetaeva, R.K., Lyssenko, K.A., Belakovskiy, D.I., Färber, G., Möhn, G. and Van, K.V. (2015) Antipinite, KNa3Cu2(C2O4)4, a new mineral species from a guano deposit at Pabellón de Pica, Chile. Mineralogical Magazine, 79, 1111–1121.Google Scholar
Clarke, R.M. and Williams, I.R. (1986) Moolooite, a naturally occurring hydrated copper oxalate from Western Australia. Mineralogical Magazine, 50, 295–298.Google Scholar
Dowty, E. (1999) ATOMS for Windows and Macintosh. Version 5.0.6. Shape Software, Kingsport, Tennessee, USA.Google Scholar
Dutton, M.V. and Evans, C.S. (1996) Oxalate production by fungi: its role in pathogenicity and ecology in the soil environment. Canadian Journal of Microbiology, 42, 881–895.Google Scholar
Eby, R.K. and Hawthorne, F.C. (1993) Structural relationships in copper oxysalt minerals. I. Structural hierarchy. Acta Crystallographica, B49, 28–56.Google Scholar
Elliott, P. (2016) Middlebackite, IMA 2015-115. CNMNC Newsletter No. 30, April 2016, page 411; Mineralogical Magazine, 80, 407–413.Google Scholar
Farrugia, L.J. (2012) WinGX and ORTEP for Windows: an update. Journal of Applied Crystallography, 45, 849–854.Google Scholar
Fomina, M., Hillier, S., Charnock, J.M., Melville, K., Alexander, I.J. and Gadd, G.M. (2005) Role of oxalic acid overexcretion in transformations of toxic metal minerals by Beauveria caledonica. Applied and Environmental Microbiology, 71, 371–381.Google Scholar
Franceschi, V.R. and Nakata, P.A. (2005) Calcium oxalate in plants: Formation and function. Annual Review of Plant Biology, 56, 41–71.Google Scholar
Francis, G.L. (2010) Minerals of Iron Monarch. OneSteel, Whyalla, South Australia, 165 pp.Google Scholar
Holland, T.J.B. and Redfern, S.A.T. (1997) Unit cell refinement from powder diffraction data: the use of regression diagnostics. Mineralogical Magazine, 61, 65–77.Google Scholar
Hunter, B.A. (1998) Rietica – A Visual Rietveld Program. Commission on Powder Diffraction Newsletter, 20, 21.Google Scholar
Jahn, H.A. and Teller, E. (1937) Stability of polyatomic molecules in degenerate electronic states. Proceedings of the Royal Society, Series A, 161, 220–236.Google Scholar
Kabsch, W. (2010) XDS. Acta Crystallographica, D66, 125–132.Google Scholar
Khomyakov, A.P. (1996) Natroxalate – Na2C2O4 – a new mineral. Zapiski Rossiiskogo Mineralogicheskogo Obshchestva, 125, 126–132 [in Russian].Google Scholar
Le Bail, A., Duroy, H., Fourquet, J.L. (1988) Ab-initio structure determination of LiSbWO6 by X-ray powder diffraction. Materials Research Bulletin, 23, 447–452.Google Scholar
Libowitzky, E. (1999) Correlation of O–H stretching …O hydrogen bond lengths in minerals. Monatshefte für Chemie, 130, 1047–1059.Google Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship: Part IV: The compatibility concept and its application. The Canadian Mineralogist, 19, 441–450.Google Scholar
Milnes, K.R. (1954) The geology and iron ore resources of the Middleback Range Area. Geological Survey of South Ausralia, Bulletin, 33, 245 p.Google Scholar
Pouchou, J.L. and Pichoir, F. (1985) “PAP” (phi-rho-z) procedure for improved quantitative microanalysis. Pp. 104 −106 in: Microbeam Analysis (Armstrong, J.T., editor). San Francisco Press, California, USA.Google Scholar
Prieto, B., Silva, B., Rivas, T., Wierzchos, J. and Ascaso, C. (1997) Mineralogical transformation and neoformation in granite caused by the lichens Tephromela atra and Ochrolechia parella. International Biodeterioration and Biodegradation, 40, 191–199.Google Scholar
Pring, A. and Birch, W.D. (1993) Gatehouseite, a new manganese hydroxy phosphate from Iron Monarch, South Australia. Mineralogical Magazine, 57, 309–313.Google Scholar
Pring, A., Kolitsch, U. and Francis, G. (2000) Additions to the mineralogy of the Iron Monarch deposit, Middleback Ranges, South Australia. Australian Journal of Mineralogy, 6, 9–23.Google Scholar
Renner, B. and Lehmann, G. (1986) Correlation of angular and bond length distortions in TO4 units in crystals. Zeitschrift für Kristallographie, 175, 43–59.Google Scholar
Rouse, R.C., Peacor, D.R., Dunn, P.J., Simmons, W.B. and Newbury, D. (1986) Wheatleyite, Na2Cu(C2O4)2·2H2O, a natural sodium copper salt of oxalic acid. American Mineralogist, 71, 1240–1242.Google Scholar
Sheldrick, G.M. (2015) Crystal Structure Refinement with SHELXL. Acta Crystallographica, C71, 3–8.Google Scholar
Yvon, K., Jeitschko, W. and Parthé, E. (1977) LAZY PULVERIX, a computer program, for calculating X-ray and neutron diffraction powder patterns. Journal of Applied Crystallography, 10, 73–74.Google Scholar
Supplementary material: File

Elliott supplementary material

Elliott supplementary material 1

Download Elliott supplementary material(File)
File 12.9 KB